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Fair value of financial instruments - Information about Significant Unobservable Inputs (Level 3) Used in Valuation of Assets Measured at Fair Value on Nonrecurring Basis (Details) $ in Thousands | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($)
--- | --- | ---
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Impaired loans |  | $ 23,810
Fair Value, Measurements, Nonrecurring |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Other real estate owned | $ 6,662 | 9,774
Impaired loans | 18,560 | 10,691
Fair Value, Measurements, Nonrecurring | Significant unobservable inputs (level 3) |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Collateral dependent loans | 18,560 |
Other real estate owned | 6,662 | 9,774
Impaired loans | $ 18,560 | $ 10,691
Fair Value, Measurements, Nonrecurring | Significant unobservable inputs (level 3) | Minimum |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Collateral dependent loans, measurement input | 0 |
Other real estate owned, measurement input | 0 | 0
Impaired loans, measurement input | 0.00% |
Fair Value, Measurements, Nonrecurring | Significant unobservable inputs (level 3) | Maximum |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Collateral dependent loans, measurement input | 0.30 |
Other real estate owned, measurement input | 0.15 | 0.15
Impaired loans, measurement input | 30.00% |

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- Definition Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524 + Details
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- Definition Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(4)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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- Definition Value of input used to measure real estate owned by financial institution by financial institution which is not directly related to its business. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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